The following disclosure relates to devices having female sockets adaptable for matably receiving complementary shaped male members. The following disclosure has particular application to apparatus and methods for retaining the male member in the female socket.
Various types of rotatably driveable devices, such as drive sockets for wrenches and socket-head threaded fasteners, are provided with a female socket recess adapted for receiving a complementary shaped male drive member. A typical form of such a driveable device has a polygonal socket recess formed in one end of the device coaxially with the axis of rotation. Various techniques have been used to facilitate retaining the driveable device on the associated driving tool or other drive member or, stated another way, to retain the driving tool or member in the socket recess.
One technique is to shape the socket recess and/or the drive member so as to provide an interference fit which will frictionally hold the parts together. Thus, for example, in U.S. Pat. No. 4,970,922, there is disclosed a fluted driving tool which is adapted for engagement in a similarly shaped socket recess, the tool and socket recess having cooperating drive surfaces. The drive surfaces in the socket recess are substantially parallel to the axis of rotation while those on the drive member are given a slight helical twist about the axis of rotation so as to afford a wedge fit in the socket recess.
Another technique is to shape a socket recess so as to provide an interference fit with a standard hexagonal shaped nut, bolt, etc. For example, in U.S. Pat. No. 5,277,531 a socket recess differs from a standard hexagonal shaped recess comprising alternating flats and corners by having built-up portions that extend between what would normally be adjacent flats of a standard hexagonal shaped recess. While perfectly adequate for some uses, this design tends to engage the corners of a nut, bolt, etc. and is not adaptable for situations where contact with the corners of the bolts is not desired. Additionally, the built up portions in this design only slope in one direction across the face of the flats, which only allows this design to achieve the maximum interference fit when the socket is turned in one of the clockwise and counter-clockwise directions, but not the other.
The disclosed apparatus and methods avoid some of the disadvantages of prior devices and methods while affording additional structural and operating advantages.
One form of the disclosed retention socket device comprises a body having a plurality of alternating drive regions and corner regions arranged about a central axis for cooperation to define a socket recess having an open outer end and an inner end. Each drive region can have a drive surface disposed thereon and confined thereto. The disclosed retention socket device can have at least one drive surface that slopes toward the central axis in directions both generally parallel to and traverse to the central axis.
One form of the disclosed method of retaining and driving a drive member comprises inserting a drive member, comprising alternating flats and corners, in a body comprising alternating drive regions and corner regions. The drive member can be releaseably retained in the body by frictionally engaging the flats of the drive member with at least two of the drive regions. The drive member can be rotated by rotating the body in one of the clockwise and counter-clockwise directions while preventing engagement of the corners of the drive member with the body.